Advantages And Disadvantages Of The Singh-Ray Vari-N-Duo Filter

One area most people don’t often experiment with is the purposeful use of long exposure times during the day. Night shots, streaking lights and star trails, are common and typically fairly easy compared to their daytime counterparts. For one thing, there’s so much light! Stopping down apertures and lowering ISOs only goes so far. The best most cameras can muster during the day is 1/10th of a second, maybe. To start adding dramatic effects to day time shots, neutral density filters can be employed.

A neutral density (ND) filter is akin to putting sunglasses on your camera, except that these sunglasses are neutral in color (although not all ND filters are made the same and some can cause a color cast). The filters are typically graded by how many stops of light they block out, such as 1 stop, 4 stops or even 9 stops. Beyond filters that are set at a particular density, variable neutral density (VND) filters can offer a wide range of effects. But not without some give and take.

I was lent a Singh-Ray Vari-N-Duo filter to find some of these limits and like most products, it has its pros and cons. This filter is listed to range from 2 2/3 stops to 8 stops in density.

First, the filter comes in two sizes; regular and slim. Regular is 17mm thick and Thin is 14mm. That little bit of thickness can make a large difference in full frame cameras and wide angle lenses, which I will cover in a moment. The filters are only available for 77mm barrels, which can be a limiting factor for some (although filter thread reducers are available to make a 77mm fit on a 62mm lens, for instance). It comes in a nice leather pouch for safe keeping.

Second, this particular filter was built with a landscape photographer in mind. The filter has two rings that rotate. The outer most ring seen in the photo above (click to enlarge) is used to set the amount of density desired; from Minimum to Maximum. The bottom ring also rotates free of the upper ring and controls a circular polarizer, negating the need to add on a second filter (which would constantly need adjusting every time a bit of density was adjusted).

Advantages

The stop range allows for a range of blur adjustment. For instance, in these photos below, the first was taken without the filter, the second was with the filter set to minimum and the third was shot with the filter on the third full mark, just before maximum. The aperture and ISO were kept the same (f/13 and 100) for all the shots. The actual shutter speeds were listed as: No filter = .6 seconds, Minimum ND = 1 second and 3rd stop = 8 seconds. It is important to note that adjustments needed to be made in Lightroom after the images were taken, resulting in exposure adjustments of 1 stop, 1.35 stops and 1.5 stops, respectively. This is mainly due to trial and error in adjusting to the filter early in the process. Shot with Canon 7D and EF 10mm-22mm lens set to 17mm.

The advantage here is the ability to give more or less blur to the water, depending on your personal preferences. While the waterfall itself does not change drastically (the brightness of which is being aided by a gradient filter in Lightroom), the water in the foreground does feel different from shot to shot. Having this ability to adjust shutter speeds via the filter can be a useful tool in changing the nuance of a bright photo.

Incorporating the polarizing filter into (and behind) the VND filter allows for easy engagement, or lack there of, in any situation. For those unfamiliar with the effects of a polarizing filter, these two shots straight from the camera which should help show a difference. Both shots were taken at 50mm, ISO 100, f/18 and 1/13 second in broad daylight with a Canon 7D and 28-300mm L lens.

The first photo is without polarization and the second photo is with.

The amount of density can be fine tuned. While each mark on the filter does not correspond to an exact amount of stops (for instance, the first mark is not 1 stop darker and the second is not 2, etc…) the filter has a way of smoothly transitioning until the last set of marks before Maximum. This allows better adjustments down low where subtle difference can make a difference. Because of the means of manufacture, once at the third mark and before Maximum, there is a large swing from about five to eight stops difference.

These really are the biggest advantages of using a VND filter with a polarizer. The ability to blur movement in broad or partial day light can be a boon to creative photographers. And the ability to control the amount of blur, while possibly keeping the aperture wide open, can lead to some interesting shots. Here are some other examples.

ISO 100, f/29, 8 seconds with Polarizer engaged

ISO 100, f/13, 3.2 seconds

ISO 100, f/13, 1/4 second

ISO 100, f/13, 6 seconds

Disadvantages

While the filter does allow for some interesting effects, it has its downside.

Price would be the biggest downside for many. The Singh-Ray Vari-N-Duo costs $390 (regular) or $440 (thin) retail. As that price is above the cost of a lot of readers’ primary lenses, it can be a tough pill to swallow and should be considered when shopping for such a filter.

Vignetting is another disadvantage. On a 16mm lens mounted to a full frame sensor camera, even the thin version will cause unwanted vignetting as the physical size of the filter can be seen in the corners of an image. This is clearly stated on Singh-Ray’s site (and was reemphasized to me by the PR rep). If you go too wide, you will encounter this effect. I could see the edge of the filter using a crop sensored Canon 7D when at 10mm (16mm equivalent). Because of the number of cameras and sizes of sensors and variety of lenses is so large, they do not give a concrete “At this focal length you will see problems”, but instead suggest zooming in a bit or changing composition.

Adjustment for those with larger hands can be a bit of an issue with the thin mount. My hands are average, as far as I know, and I was able to make adjustments without much problem. It is best to use two hands while adjusting the polarizing filter which will require a tripod most of the time. Granted, this filter is often used with a tripod, but sometimes it can be used to achieve a wider aperture in daylight.

Metering is also fuddled when the filter is on. Going by what my camera suggested for ‘proper’ metering often left images too dark. I found I had to make a chart showing how much I should compensate at different marks on the filter. But this didn’t hold true in every case. What I’m trying to say, is there is a learning curve to using the filter and you will need to take it slow when first employing it. With practice, it becomes easier.

Focusing is also difficult when the filter is stopped all the way down. Manual focus must often be used when darker settings are employed.

Only available for in 77mm diameter.

The Singh-Ray Vari-N-Duo is a fun filter to use and, when given specific application, can yield some shots most can not achieve without it. My time testing the filter was too short as I would have liked to get into more varied situations (it also would have been helpful if it was more sunny in Seattle this year!). Right now the price tag has me holding back from pulling the trigger on a purchase. Yet with trips to Nepal, Bhutan, India and Peru this fall I am itching to snag one, knowing it will surely help me bring back lively photos.

Some Older Comments

Swap KMay 5, 2012 02:27 am

This question is for all photographers who use the Vari-N-Duo. My images with the Vari-N-Duo appear to have a yellowish / grey color cast (with the ND setting at Min) as opposed to the same images shot without the filter. In the images that I shot, the water appears dull and same is the case of the surrounding rocks / foliage.

Can anyone using the Vari-N-Duo let me know if the dull yellow / grey color cast is a characteristic of this filter ? Do you post process in Lightroom or any other software to remove any color cast and render the true colors in the images as seen on this site ? My images with the Vari-N-Duo straight out of the camera appear nowhere close to the vibrant, colorful and alive images seen on this site.

Any help from you folks is most welcome and very much appreciated.

Photography workshops in new zealandMay 4, 2012 07:50 am

The issuers with exposure being out -that the author mentioned - when using strong ND filters, are often caused by light entering the view finder. A lot of cameras come with an ability to block this light, and when used, solves the exposure problem.

EricMay 4, 2012 05:13 am

Step down rings are inexpensive and easily portable. Unless you're one of those people who takes the cardboard tube out of toilet paper rolls to save weight, the stepping rings won't be an issue.

I have this filter and find it absolutely indispensable. I like having a polarizer and variable ND filter on the same body. I use the 16-35mm Nikon ultrawide with a D700 body, and you will get bad vignetting between 16-24mm on the slim filter. A wider aperture mitigates this but for landscapes I mostly shoot at f/11 f/16.

The vignette really isn't much of an issue, I simply compose my shot starting at 24mm, or I give the shot some edge room so I can crop out the vignette later, if I need to shoot below 24mm.

Another commenter mentioned the convenience of being able to dial in the ND, and it is very handy, not having to remove the filter just to refocus.

The price is high but you're getting a VERY good product.

Swap KApril 26, 2012 05:34 am

I just started using the Vari-N-Duo. However, my images with the Vari-N-Duo appear to have a yellowish / grey color cast (with the ND setting at Min) as opposed to the same images shot with the LB Color Combo. In the images that I shot, the water appears dull and same is the case of the surrounding rocks / foliage.

Can anyone using the Vari-N-Duo let me know if the dull yellow / grey color cast is a characteristic of this filter ? Do I need to post process in Lightroom and adjust the White Balance to render the true colors as seen by the eye ?

Any help is most appreciated.

JimAugust 22, 2011 11:30 am

Thanks for the review. I was wondering how well Variable ND filters work. As for myself, since I already have 4 screw on ND filters of different stops and a Cokin Z pro system with several ND filters, I think I'll stick with them. Yes, it's not as convenient as the variable ND but they don't take up much room and I don't have any vignetting problems.

Erik KerstenbeckAugust 20, 2011 12:07 pm

@ Mike - stacking two CP filters is what Singh-Ray does

Erik KerstenbeckAugust 20, 2011 12:06 pm

Hi

Had another session with the thin Singh-Ray today with mixed results. The Sigma 10-20mm produced aweful X-vignetting. I am really disappointed since this is my Landscape Lens! Switched to the f2.8 Nikon 70-200mm and got decent results. I am still searching for a way to get it to work for my Sigma. Beth Sandidge told me to zoom out and it worked, but this defeats the purpose of this fine glass - ideas anyone?

TC, You get the same effect from the Singh-Ray if you push it past Maximum. While it will darken a bit more, those blotches will appear because you went beyond 8 stops.

kre, As for stopping down with a ring, it would matter on the depth of the step-down ring, but that is highly likely to work well.

Akshay VermaAugust 16, 2011 04:27 am

Are you coming to Ahmedabad, Gujarat, India by any chance? I you are then please pay us a visit at the National Institute of Design. We would be really grateful if we get a chance to interact with you :)

KREAugust 16, 2011 03:54 am

On the point with vignetting, the lens you shot with was a 77mm width. Do you think it would still be an issue at wider focal lengths if the lenses had a smaller opening and used a step-down ring to mount the filter (ie Tamron 17-50mm has a 67mm width, would it still show vignetting on a crop body)?

Thanks for the review and your other articles!

TCAugust 16, 2011 03:16 am

I did some test shots with my Cameron ND Fader (no polarizer) when I was out shooting in bright daylight around noon in a parking lot. With the filter set to maximum, the photo that came out was way too dark. When I increased the exposure to get more details, I was surprised to find two patches in the photo that are darker then the rest of the picture, located diagonally opposit each other in the frame. I am wondering if this is a common probllem wth all ND Faders. (It was shot at 11mm on the D7000, equivalent to around 16mm on 35mm film camera).

I don't consider the one size only policy a limitation. 77mm wil cover 99% of all the lenses out there, and it allows the filter to be used on wide angle lenses with smaller filter threads with less or no vignetting. It is cheaper to buy a few stepping rings at 10-15 each than buying additional filer(s) for each lens size.

By the way, in addition to being thin, the Cameron fader is made slightly larger to reduce/avoid vignetting.

FuzzypiggyAugust 15, 2011 10:17 pm

The price is the biggest hit. You can get a Lee holder, a set of ND grads and still have change for a circular polarizer or Big Stopper. OK the minute control of the stop is not possible with fixed glass/resin filters but you at least get something you can use on huge wide-angles ( 80mm+ ) down to small ( 68mm or less ) sizes, all you need is a few adpater rings in your bag. The Lee kit is the only filter system I have had the least amount of vingette issues with, alright I'm biased as they are a UK company ( supporting my home country manufaturers! ) but when the likes of Lee Frost and Joe Cornish support Lee, they're good enough for an amatuer like me!

John MaddenAugust 15, 2011 01:53 pm

There is also an article on this website on creating your own variable ND filter I just discovered.

The LightCraft Workshop Fader ND is about half the price of the Singh-Ray, and apparently is pretty good. I learnt about the Fader ND when I read this review.
I'd like to see a side-by-side comparision between the Fader ND and the Singh-Ray, to see exactly how the image quality compares.

ACAugust 15, 2011 07:47 am

You could always save yourself some money & make your own with two polarisers. This is the same thing anyway ;)

I recently purchased the Variable ND from Singh-Ray and equipped it on a 10-20mm Sigma on a Nikon D7000 to shoot some "smokey" ocean vistas of the San Diego Coast. I had not used this combination before and was shocked to find strange X-hatched darkened areas depending on the ND setting. I read that often this filter does not work with wide lenses. I was expecting something like this:

I will keep the filter and figure out how best to use it, but it wasn't as obvious as I originally was thinking. Perhaps a single ND would do a better job than this stacked X-Polarization filter! Hmmm...

OsmosisStudiosAugust 15, 2011 06:07 am

There's also a HUGE colour cast (note the red in the last shot of the harbor pier)

Jake TownsenAugust 15, 2011 05:42 am

Another benefit of this filter, or any ND, is when shooting off camera flash portraits outdoors in daylight/sunset. Usually to achieve good lighting you need to stop down the aperture since your shutter is limited to a 200 or 250 sync. This in broad daylight means f13 or lower. With the ND you can shoot around f5.6.

Benefits? DOF, less intense flash power, and unless you are a clean sensor freak...way less dust spots on your final shot. :)

I see a lot of video guys using this vari ND when they shoot outdoors and want to keep the aperture wide open at 1.2 or 1.4 on a prime. They can keep the shutter around 60 and still get that look.

NickAugust 15, 2011 04:09 am

Everytime I'm here, I always learn a new trick. Amazing how subtle changes make a big difference. That waterfall/woods shot is incredible btw :)

Lewis McLeodAugust 15, 2011 04:05 am

I have to say that while Mr. Lopez's method is certainly simpler and carries a smaller learning curve, for those who pack their gear on foot, one filter that does two jobs is a fantastic idea. Unfortunately, Singh-Ray has sort of undone that advantage by putting it out in a single diameter. How many people want to carry around a bunch of stepping rings? Sadly, the pricetag is the largest deterrent for me... although it's one more thing to add to my camera's wish-list

dokAugust 15, 2011 03:27 am

Definitely the price is a problem!
For this effect I use the combination of two polarasing filters. But at least one has te be a linear one (two circular polarizer don't do the trick).

Brian HoffmanAugust 15, 2011 03:07 am

Wish I'd known about it. I'm committed to using the Lee Big Stopper.

John MaddenAugust 15, 2011 03:04 am

There is another very inexpensive way to make your own variable ND filter with two polarizers combined. The amount of light passing thru goes to zero as you rotate them relative to one another. I would recommend a custom white balance adjustment when doing this because there is a color shift. Here is an article on a website about it. It's probably not the most professional solution but, if you just want to play with longer exposure times it works great.

I bought a filter from a company called Genius that was 90 dollars and does the same thing. And it's available in different sizes. I've taken 6, 8, even ten second exposures in bright daylight.

TimAugust 15, 2011 02:19 am

Nice review. I recently purchased on of these filters for a West Virginia Waterfall workshop I took a few months ago (http://radiantviewphotography.blogspot.com/2011/06/west-virginia-workshop.html). I was using a full frame camera (Canon 5D Mk II) and I found that, on my 24-105 lens, I would get vignetting between 24 and 30 mm. The vignetting at 24mm was pretty severe with the corners being completely black. I purchased the standard version, so the effect would be less with the slim model.

The only part of your review I think needs some added clarification is your comment in the disadvantage section that "Focusing is difficult when stopped all the way down." I would content this is actually one of the main advantages of the vari-N-duo. Just turn the dial to reduce the amount of ND filtration, adjust your focus, then dial back in the right amount of ND filtration. With standard ND filters, this would be much more difficult as you would have to physically remove the filters.

Thanks for your review.

Robbie LopezAugust 15, 2011 01:24 am

There is an easier and cheapter solution.
1. Buy a Cokin filter holder.
2. Buy a few different Cokin ND filters and/or circular polarizer.

More customization. Just as if not more effective, no vignette, and it costs less than 1/2 the price of the Singh-Ray Vari-N-Duo.